I live in Australia and purchased an unlocked iphone from America about 4 months ago. It has alread been unlocked so that i can use it on my local TELSTRA Ausralia network, utube, google earth etc.

The current software version on the phone is 1.0.2.

I have had no problems so far and my motto has been "if it isn't broken then don't fix it". however recently i have had clitches in the software starting to appear and last night it completely shut down and wouldn't start up again. i finally got it re-booted this morning but i think upgrading the software to the most recent one will correct a lot of these poblems.

The questions i have are:
1. Do i just need to follow the guide to upgrade my software to 1.1.3, or will i have to then unlock the phone as well and do a few other things to get it compatible with the australian networks?
2. When i upgrade, will all of my contacts and internet settings etc be lost?
3. Are there any special things i need to do when im upgrading if the phone is to be used on Ausralian phone networks and not American
4. My home computer recognises my iphone and i can sync it but on my work computer it isnt recognising it at all? is there something small i need to do to rectify this? im using microsoft windows xp.